How to SELECT with optional columns?

I'm currently working on a c# application that grabs a bunch of data from a user specified access(.mdb) database and does a bunch of stuff with that data. A problem that I've recently come across is that some of the a database is missing a column that has existed in all of the others.

How can I do a select on a database, but gracefully fail (throw null in the data or something) when a column doesn't exist in the database?

Currently, my code looks something like this:

OleDbConnection aConnection = new 
    OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + FileName);

string sqlQuery = "SELECT [Table1].[Index], [Table1].[Optional Info], 
    [Table2].[Other Info], .... 
    FROM [Table1] INNER JOIN [Table2] ON [Table1].[Index]=[Table2].[Index] 
    ORDER BY [Table1].[Index]";

OleDbCommand aCommand = new OleDbCommand(sqlQuery, aConnection);
OleDbDataReader aReader = aCommand.ExecuteReader();

(proceed to read data in line by line, using fabulous magic numbers)

I think it's obvious that this is one of my first experiences with databases. I'm not overly concerned as long as it works, but it's stopped working for a database that does not contain the [Table1].[Optional Info] column. It's throwing an OleDbException: "No value given for one or more required parameters."

Any help would be appreciated.

Solution

I might be missing something but...

SELECT Table1.*, Table2.otherInfo
FROM ...

Should do the trick, and let the client process the result set, with an important caveat: there is no way to exclude a column from Table1 in the above.

(I am not aware of any method to "dynamically shape" -- with the viewpoint of the caller -- a SELECT except with a * in the column list as above.)

Happy coding.